The present invention relates to catheters and more particularly to a catheter having one or more lumens therein and an integral anchoring mechanism along the hub member of the catheter to facilitate suturing and removal of the catheter from the body of the patient.
Single or multiple lumen catheters are well known in the medical field and are widely used in medical procedures such as hemodialysis or other procedures wherein it is desirable to inject or remove fluids through one or more lumens of the catheter. For example, in hemodialysis it is desirable to remove blood from a vein or other vessel of a patient through a first lumen of a catheter while returning a corresponding amount of dialyzed blood to the patient through another lumen of the catheter. In certain situations, it may also be desirable to have a third lumen extending through the catheter to allow a medication to be injected therethrough without interfering with the operation of the first or second lumens.
The currently available single or multiple lumen catheters typically include a distal section having a tip member thereon; an elongate body portion which extends proximally from the tip portion; a catheter hub or hub member on the proximal end of the body portion; and one or more extension members which are used to inject and/or remove fluids from the catheter. Additionally, if the catheter is intended to be used for longer term therapy, such as in long term dialysis applications in excess of thirty days, the body portion of the catheter may also include a cuff thereon to allow the tissue of the patient to grow into the cuff. The growth of the tissue into the cuff of the longer term catheter helps to seal the catheter tunnel tract and also stabilizes the catheter in the body of the patient. The hub member of the catheter is frequently sutured to the body of a patient to minimize the movement or migration of the catheter in the catheter tunnel tract of the patient and secondarily to inhibit movement of the distal end of the catheter in the blood vessel of the patient once the catheter has been inserted to the desired position.
Various catheter hub designs have been used to facilitate the attachment of the catheter to the body of the patient. These designs may be grouped generally into designs which allow the physician to wrap the suture through the skin of the patient and around the catheter hub; designs which provide tab members which enable the physician to pass the suture through the skin of the patient and the tab member or designs which allow both.
In catheters which are intended to be used in a patient for relatively long periods of time, the hub member functions as a temporary method of limiting the movement of the catheter while tissue is allowed to grow into a cuff member which is located on the catheter body. With the longer term catheters, a physician may remove the suture from around the hub member approximately one week after the catheter was implanted into the patient so that the catheter is retained in the desired position by the tissue of the patient which has grown into the cuff in the catheter tunnel tract. In short and long term catheters, it is occasionally necessary for the physician to reposition the catheter or remove the catheter from the body of the patient; therefore, it is desirable to provide an attachment mechanism which provides secure and flexible attachment of the catheter to the body of the patient while allowing for the easy removal of the catheter from the body of the patient when necessary. Although the prior hub member designs which allow the physician to wrap the suture around the hub member of the catheter are simple to use, these designs have the disadvantage that the suture has a tendency to pull out of the skin of the patient if the patient moves excessively or accidentally bumps the proximal portion of the catheter. With these designs, the suture may also damage the hub member if the suture is wrapped or tied too tightly around the hub member. Additionally, it is more likely that the physician may accidentally cut or nick the hub member of this design while attempting to secure the catheter to the skin of the patient or during removal or repositioning of the catheter member than with other hub member designs. Another disadvantage to this type of hub member design is that inconsistent hub rotation forces may arise depending on the how tightly the suture is tied around the hub member.
In the catheter hub member designs which allow the physician to wrap the suture through tab members, the suture is threaded through the skin of the patient and then through the openings in the tab members. The ends of the suture are then tied together to secure the tab member and catheter to the patient. In this type of design, it is important that the tab members have sufficient flexibility to allow the tab members to flex in response to movement of the patient in order to avoid tearing the suture from the skin of the patient or irritating the patient at the suture location. Another consideration in this type of hub member design is that the tab members must have sufficient strength to prevent the suture from cutting the tab members and pulling out of the tab members. Additionally, it is important to have openings in the tab members which are sufficiently large to allow the physician to easily pass the suture through the opening in the tab member at the end of the placement procedure. Finally, it is important for the hub member design to allow for the easy and rapid removal of the sutures from the tab and hub members and the body of the patient. Various commercially available catheter hub member designs of the type described above are shown in FIGS. 1-6, none of which meet all of the preferred characteristics for a hub member.
The hub member of the present invention meets the preferred characteristics and overcomes the disadvantages described above by providing loop members which have an increased relative flexibility while providing an enlarged opening to allow for suturing between the hub member and the loop member. The loop member of the present invention still maintains the structural strength necessary to prevent to suture from tearing through the loop members if the patient moves excessively and provides sufficient flexibility to accommodate normal movement of a patient without tearing the skin of the patient.
The loop members of the present invention are also designed to be easily cut off flush with the side of the catheter once the tissue of the patient has grown into the cuff on the body portion of the long term catheter while minimizing the likelihood that the catheter body or hub member will be nicked or cut during removal of the loop members.
In one form of the present invention, the loop members are also designed to be rotatable with respect to the body of the catheter in short term catheters to allow the catheter to be easily rotated or repositioned with respect to the skin of the patient while minimizing the likelihood that the catheter body or hub member will be nicked or cut during rotation or repositioning of the loop members.
The present invention is directed to an improved design for securing the hub member of the catheter to the body of a patient. This design, when used properly, reduces migration and movement of the catheter relative to the catheter tunnel tract of the catheter in the skin of the patient and minimizes the likelihood that the suture will be torn from the skin of the patient during normal patient movement. Additionally, the securement points or loop members are spaced apart from the catheter body and hub member to reduce the likelihood that the catheter body and/or hub member will be damaged during the placement, repositioning and removal procedures.
In one form of the present invention, the hub member is preferably formed of a flexible or elastomeric material such as a silicone or similar material and includes a tubular shaped member having a pair of generally loop shaped members which may be formed of a material which is similar to the material of the tubular member. The loop members preferably extend laterally from the sides of the tubular member and are preferably formed or otherwise bonded or affixed as part of the tubular member. The tubular member and loop members may also be formed as a separate or integral part of the hub member of the catheter. The cross sectional and inner and outer diameter dimensions of the tubular member and loop members may be readily modified to form loop members having the desired design features such as moderate stiffness, increased cut resistance and increased patient comfort.
In an alternate form of the hub member of the present invention, the tubular member and loop members are preferably rotatable with respect to the body of the catheter. In this embodiment, the tubular member may be rotatable with respect to the hub member and body portion of the catheter while the longitudinal and/or lateral positioning of the tubular member with respect to the catheter body is maintained by receiving a portion of the tubular member in a groove and recess or similar feature on the hub member and tubular member.
The hub member of the present invention is preferably used with a single or multiple lumen catheter such as a dual or triple lumen catheter which may be used for infusion, apheresis and/or hemodialysis treatments of the patient. The catheter may also preferably include at least one generally D-shaped lumen therein. If the hub member is used with an infusion, apheresis and/or hemodialysis catheter the body portion of the catheter preferably includes a blood return or first lumen which extends between the proximal end of the body portion of the catheter and a distal opening on the catheter tip which is located at the distal end of the catheter. The intake or secondary lumen of this type of catheter preferably extends between the proximal end of the body portion of the catheter and a side opening which is preferably located along the distal portion of the catheter and is generally proximal to the catheter tip.
An object of the present invention is to provide a hub member which includes a tubular member having a pair of loop members thereon to provide improved flexibility between the secured catheter and the skin of the patient while limiting movement of the catheter relative to the catheter tunnel tract and/or exit site.
Another object of the present invention is to provide a hub member having a pair of loop members thereon which are shaped and oriented with respect to the hub member to allow for the easy removal of the loop members from the hub member to enable the easy detachment of the hub member from the skin of the patient.
Yet another object of the present invention is to provide enlarged openings between the tubular member and the loop members of the hub member to allow for the easy passage of the suture therethrough as the hub member is attached to the body of the patient.
Yet another object of the present invention is to provide a hub member having flexible loop members extending laterally therefrom to minimize the likelihood of the suture being torn from the skin of the patient during normal movement of the patient.
Yet another object of the present invention is to provide enlarged openings between the tubular member and the loop members of the hub member to minimize the bulk and weight of the hub member.